What was found
CABIN EMERGENCY LIGHTS BEGAN FLASHING IN CRUISE FLIGHT. RECEIVED MODIFIED EMERGENCY BATTERY P/N: 7450LS-00, S/N: 000915M. REMOVED AND REPLACED # 2 BATTERY PACK P/N: SAME, S/N: 005763 LOCATED IN THE LAV. USING GPU CHARGED PACK FOR THIRTY MINS. DISCONNECTED # 1 BATTERY IN THE COCKPIT. SET EMER SWITCH TO ARM AND VERFIED EMER LIGHTS WERE NOT FLASHING AND OFF. OPS CHECK GOOD. RECONNECTED # 1 BATTERY PACK CONNECTOR AND CHARGED PACKS FOR ANOTHER THIRTY MINS BEFORE SHUTTING DOWN GROUND POWER, APPLIED DATE,TIME, AIRPORT IDAND TECH STAMP ONTO BATTERY PACK. WORK DONE IAW PHENOM 300 M.M. 33-52-01 AND FIM 33-50-00.